Read apparatus of RF tag and method of controlling read of RF tag

ABSTRACT

An RF tag system includes a first reader/writer unit and a second reader/writer unit. A first reader/writer control unit is configured to control the first reader/writer unit to read a first data from a first RF tag, and to detect a trouble state of the first reader/writer unit. A second reader/writer control unit is configured to control the second reader/writer unit to read a second data from a second RF tag, and to detect a trouble state of the second reader/writer unit. A monitoring section is configured to issue a selection instruction and to monitor the first reader/writer unit through the first reader/writer control unit, and the second reader/writer unit through the second reader/writer control unit. A switching section is configured to select one of the first reader/writer control unit and the second reader/writer control unit in response to the selection instruction from the monitoring section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a read apparatus for an RF tag, andmore particularly relates to a redundancy in a read apparatus for an RFtag and a controlling method for the same.

2. Description of the Related Art

An RF (Radio Frequency) tag reader/writer apparatus can perform a radiocommunication with an RF tag and read ID (Radio FrequencyIdentification) of the RF tag. As for a trouble of the RF tagreader/writer apparatus, it may be considered to use two or more RF tagreader/writer apparatuses and ensure its redundancy. However, if the twoRF tag reader/writer apparatuses are installed separately from eachother, there is a problem which of the RF tag reader/writer apparatusesis used when the ID of the RF tag is read. If they are installed closeto each other, there is a possibility of interference of an electricwave.

In conjunction with the above description, Japanese Laid Open PatentApplication (JP-P2005-157645A: first conventional example) discloses aread apparatus. In this conventional example, the read apparatus for aradio tag in which an identification code is recorded without anycontact. This read apparatus includes a plurality of reader apparatusesto which a plurality of antennas are connected. A controller performs acontrol in which one antenna connected to each reader apparatus isturned on when a plurality of tags are located at a read region of theread apparatus. Thus, the adjacent antenna is not turned on, and theplurality of radio tags inside the read region are consequently read.

Also, Japanese Laid Open Patent Application (JP-P2005-339089A: secondconventional example) discloses a non-contact ID system. Thisconventional non-contact ID system includes a plurality of answerers, aquestioner and a host manager. The plurality of answerers store peculiaridentifiers, and meet communication standard different from each other.The questioner contains a plurality of signal processing sections and acontrol section. The plurality of signal processing sections send aplurality of question signals are transferred to the answerers based onthe respective communication standards. The signal processing sectioncontains a plurality of signal processors, each of which receives theanswering signal including the identifier replied by the answererreceiving the question signal of the communication rule agreeing withitself. When receiving the external question request, the controlleroutputs a drive command or stop command to its signal processor. Thehigh order manager outputs the question request to send the questionsignal based on any of the communication rules to the answerer.

When sending the question signal based on any of the communicationstandards to the questioner, the host manager sends a question requestcorresponding to the communication rule. Then, the controller of thequestioner outputs the drive command to the signal processorcorresponding to the communication rule. On the other hand, thecontroller outputs the stop command to the signal processorscorresponding to the communication rules except it. This non-contact IDsystem has such feature.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide anapparatus for reading an RF tag, which reserves a redundancy of an RFtag reader/writer apparatus while managing a plurality of RF tagreader/writer apparatuses arranged close to each other and avoidingtheirs interference, and a method of controlling an RF tag reading.

In an aspect of the present invention, an RF tag system includes a firstreader/writer unit; a second reader/writer unit; a first reader/writercontrol unit configured to control the first reader/writer unit to reada first data from a first RF tag, and to detect a trouble state of thefirst reader/writer unit; a second reader/writer control unit configuredto control the second reader/writer unit to read a second data from asecond RF tag, and to detect a trouble state of the second reader/writerunit; a monitoring section configured to issue a selection instructionand to monitor the first reader/writer unit through the firstreader/writer control unit, and the second reader/writer unit throughthe second reader/writer control unit; and a switching sectionconfigured to select one of the first reader/writer control unit and thesecond reader/writer control unit in response to the selectioninstruction from the monitoring section.

Here, the monitoring section may issue the selection instruction to theswitching section to select the second reader/writer control unit whenthe trouble state of the first RF tag reader/writer unit is confirmed.

Also, the monitoring section may issue a monitor instruction to thefirst reader/writer control unit to detect recovery of the first RF tagreader/writer unit from the trouble state, when the trouble state of thefirst RF tag reader/writer unit is confirmed.

Also, the RF tag system may further include a communication controlsection configured to communicate with an external network and totransfer a data request from the external network to the switchingsection to acquire a data of the first RF tag or second RF tag.

Also, the first RF tag and the second RF tag may be a same singlereference RF tag provided for operation confirmation, and the first andsecond RF tag reader/writer units may access the reference RF tag.

In another aspect of the present invention, a method of controlling aread operation from an RF tag, is achieved by issuing an instruction toa switching section to use a first RF tag reader/writer control unit; byinquiring the first RF tag reader/writer control unit to check whetherthe first RF tag reader/writer unit is in a trouble state; by continuingto use first RF tag reader/writer control unit by the switching sectionif the first RF tag reader/writer unit is not in the trouble state; byissuing an instruction to the switching section to use a second RF tagreader/writer control unit, when it is confirmed that the first RF tagreader/writer unit is not in the trouble state; by inquiring first RFtag reader/writer control unit to confirm whether the first RF tagreader/writer unit has been recovered from the trouble state, when it isconfirmed that the first RF tag reader/writer unit is not in the troublestate; and by issuing an instruction to the switching section to use thefirst RF tag reader/writer control unit, when it is confirmed that thefirst RF tag reader/writer unit has been recovered from the troublestate.

Also, the method may be achieved by further issuing a data read requestfrom an application connected to an external network; receiving the dataread request from the application and transferring the data read requestto the switching section; and controlling one of the first RF tagreader/writer control unit and the second RF tag reader/writer controlunit in response to the data read request to read a data from the RFtag.

Also, the method may be achieved by further issuing a read instructionto the first RF tag reader/writer control unit to read a data from theRF tag, when it is confirmed that the first RF tag reader/writer unit isnot in the trouble state; and controlling the first RF tag reader/writerunit to access the RF tag to read the data by the first RF tagreader/writer control unit in response to the read instruction.

Also, the method may be achieved by further issuing a read instructionto the second RF tag reader/writer control unit to read a data from theRF tag, when it is confirmed that the first RF tag reader/writer unit isin the trouble state; and controlling the second RF tag reader/writerunit to access the RF tag to read the data by the second RF tagreader/writer control unit in response to the read instruction.

In still another aspect of the present invention, a method ofcontrolling a read operation from an RF tag, is achieved by issuing aselection instruction to a switching section to select a first RF tagreader/writer control unit; by reading a data from a reference RF tag bya first RF tag reader/writer unit through the first RF tag reader/writercontrol unit; by continuing to select the first RF tag reader/writercontrol unit by the switching section if the data can be read out fromthe reference RF tag; by issuing the selection instruction to theswitching section to select a second RF tag reader/writer control unitwhen the data cannot be read out from the reference RF tag; bymonitoring whether the data can be read out from the reference RF tag bythe first RF tag reader/writer unit, through the first RF tagreader/writer control unit in order to detect recovery of the first RFtag reader/writer unit from a trouble; by continuing to monitor thefirst RF tag reader/writer unit when the data cannot be read out fromthe reference RF tag by the first RF tag reader/writer unit; and byissuing the selection instruction to the switching section to select thefirst RF tag reader/writer control unit when the data can be read outfrom the reference RF tag.

Here, the method may be achieved by further discarding the data read outfrom the reference RF tag; neglecting a read/write instruction for thereference RF tag; and informing to an application, a list of identifiersof RF tags, from which the identifier of the reference RF tag isremoved, in response to a read request of the identifiers of the RF tagsfrom the application.

When the plurality of RF tag reader/writer units are provided close toeach other, the redundancies of the RF tag reader/writer apparatuses canbe reserved without any electric wave interference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of a first embodimentof the present invention;

FIG. 2 is a flowchart showing operations of the first embodiment of thepresent invention;

FIG. 3 is a block diagram showing a configuration of a second embodimentof the present invention; and

FIG. 4 is a flowchart showing operations of the second embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an RF (radio frequency) tag system according to the presentinvention will be described in detail with reference to the attacheddrawings.

FIG. 1 is a block diagram showing the configuration of an RF tag systemaccording to the first embodiment of the present invention. As shown inFIG. 1, the RF tag system according to the first embodiment of thepresent invention contains a controller 10, RF tag reader/writer units20 (20-1, 20-2), antennas 30 (30-1, 30-2) and an RF tag 40.

The controller 10 controls the RF tag reader/writer units 20. The RF tagreader/writer unit 20 (20-i, i=1 to n: n is the number of apparatuses)uses the antenna 30 and carries out a communication. Also, the RF tagreader/writer unit 20 uses the antenna 30 to read an identifier (ID) anda data from the RF tag 40 and starts or stops an RF output. Here, as anexample, the RF tag reader/writer unit 20-1 and the RF tag reader/writerunit 20-2 are used. The antenna 30 (30-i, i=1 to n) sends and receivesan electric wave to and from the RF tag 40. Also, when the RF tag 40 isplaced at a predetermined position, its position and orientation areadjusted and installed to be able to communicate with any antenna. Also,the antenna 30-1 and the antenna 30-2 are used. The RF tag 40 holds adata containing an ID. At this time, the controller 10 contains acommunication control section 11, a reader/writer apparatus switchingsection 12, a reader/writer monitoring section 13 and a reader/writercontrol sections 14 (14-1, 14-2).

The communication control section 11 performs communication with anexternal network and accesses to the RF tag 40 through the reader/writerswitching section 12 in accordance with an request or instruction froman application in the network and the like. The reader/writer switchingsection 12 selects the RF tag reader/writer control section 14 to beused in accordance with a selection instruction from the reader/writermonitoring section 13. That is, the reader/writer control section 14 tobe used is switched. The reader/writer monitoring section 13periodically monitors a trouble in the RF tag reader/writer units 20through the reader/writer control sections 14. The reader/writer controlsections 14 (14-i, i=1 to n) instruct the RF tag reader/writer units 20to read the ID of the RF tag 40 close thereto, to read and write a datafrom and to a memory inside the RF tag 40, to detect a trouble state andto start or stop the RF output. Here, as an example, the reader/writerapparatus control section 14-1 and the reader/writer apparatus controlsection 14-2 are used.

The operation of the RF tag system in this embodiment will be describedbelow in detail with reference to FIG. 1.

The process of the reader/writer monitoring section 13 will be describedbelow with reference to FIG. 2.

(1) Step S101

At first, the reader/writer monitoring section 13 issues a selectioninstruction to the reader/writer switching section 12 to select thereader/writer control section 14-1.

(2) Step S102

Next, the reader/writer monitoring section 13 issues a read instructiondirectly or through switching section 12 to the reader/writer controlsection 14-1 to check whether or not the RF tag reader/writer unit 20-1is in a trouble state.

(3) Step S103

If the RF tag reader/writer unit 20-1 is not in the trouble state, thereader/writer switching section 12 may continue to select thereader/writer control section 14-1, and the operational flow returns tothe step S102 in its original state.

(4) Step S104

If the RF tag reader/writer unit 20-1 is checked to be in the troublestate, the RF tag reader/writer unit 20-1 cannot be used. In this case,the reader/writer monitoring section 13 issues the selection instructionto the reader/writer switching section 12 to select the reader/writercontrol section 14-2 in order to use the RF tag reader/writer unit 20-2.

(5) Step S105

Next, in order to monitor the recovery of the RF tag reader/writer unit20-1 from the trouble, the reader/writer monitoring section 13 issues amonitor instruction to the reader/writer control section 14-1 to checkwhether or not the RF tag reader/writer unit 20-1 is still in thetrouble state. The monitor instruction may be periodically performed orthe check may be periodically performed. Or, this check is performedwhen the use of the RF tag reader/writer unit 20-2 has been completed.

(6) Step S106

If the RF tag reader/writer unit 20-1 is troubled, the operational flowreturns to the step S105 in its original state. If the RF tagreader/writer unit 20-1 is checked to be recovered from the trouble, theRF tag reader/writer unit 20-1 can be used. Thus, the operational flowreturns to the step S101, in order to instruct the reader/writerswitching section 12 to use the reader/writer control section 14-1.

It is assumed that an application connected to the external networkissues a read request of a tag ID of a reader/writer apparatus. Thisrequest is received by the communication control section 11, and theread request is issued to the reader/writer switching section 12. Thereader/writer switching section 12 transfers the read request to any ofthe reader/writer control section 14-1 and the reader/writer controlsection 14-2 in accordance with an instruction of the reader/writermonitoring section 13.

If the RF tag reader/writer unit 20-1 is not troubled, the reader/writerswitching section 12 transfers the request to the reader/writer controlsection 14-1. As a result, the reader/writer control section 14-1 issuesthe read request to the RF tag reader/writer unit 20-1, and the RF tagreader/writer unit 20-1 uses the antenna 30-1 to read the data from theRF tag 40.

If the RF tag reader/writer unit 20-1 is troubled, the reader/writerswitching section 12 transfers the read request to the reader/writercontrol section 14-2. As a result, the reader/writer control section14-2 issues the read request to the RF tag reader/writer unit 20-2, andthe RF tag reader/writer unit 20-2 uses the antenna 30-2 to read thedata of the RF tag 40.

In the RF tag system according to the embodiment of the presentinvention, a case that the number of the RF tag reader/writerapparatuses is 2 has been described. However, the number of the RF tagreader/writer apparatuses is not limited.

A case that the application which actually processes the RF tag dataexists in the external network has been described. However, there isalso a case that the application exists in the same apparatus as thecontroller 10 or it is connected by using a different method.

Second Embodiment

The RF tag system according to the second embodiment of the presentinvention will be described below in detail with reference to theattached drawings. With reference to FIG. 3, the second embodimentdiffers from the first embodiment in that there is a reference RF tag41.

That is, the RF tag system in the second embodiment contains thecontroller 10, the RF tag reader/writer units 20, the antennas 30, theRF tag 40 and the reference RF tag 41. The controller 10, the RF tagreader/writer units 20, the antennas 30 and the RF tag 40 are similar tothose of the first embodiment. The reference RF tag 41 is provided at aposition where it can be read from both of the antenna 30-1 and theantenna 30-2. The reference RF tag 41 is provided to check theoperations of the antennas 30. The RF tag 40 provided at the positionwhere it can be read from any of the antennas 30 may be used as thereference RF tag 41. Or, a dummy RF tag that stores the meaningless datamay be used as the reference RF tag 41.

The process of the reader/writer monitoring section 13 in thisembodiment will be described below with reference to FIG. 4. In thisembodiment, instead of the check of the trouble of the RF tagreader/writer apparatus, the reading operation of the RF tag 41 ischecked.

(1) Step S201

At first, the reader/writer monitoring section 13 instructs thereader/writer switching section 12 to use the reader/writer controlsection 14-1.

(2) Step S202

Next, the reader/writer control section 14-1 controls the RF tagreader/writer unit 20-1 to read the ID of the reference RF tag 41.

(3) Step S203

If the RF tag reader/writer unit 20-1 can read the ID of the referenceRF tag 41, the RF tag reader/writer unit 20-1 and the antenna 30-1 canbe considered to be normally operated. Thus, the reader/writer switchingsection 12 continues to use the reader/writer control section 14-1, andthe operational flow returns to the step S202 in its original state.

(4) Step S204

If the RF tag reader/writer unit 20-1 cannot read the ID of thereference RF tag 41, the trouble of the RF tag reader/writer unit 20-1or antenna 30-1 is considered. Thus, the reader/writer monitoringsection 13 instructs the reader/writer switching section 12 to use thereader/writer apparatus control section 14-2.

(5) Step S205

Next, in order to monitor the recovery of the RF tag reader/writer unit20-1 and the antenna 30-1 from the trouble, the reader/writer controlsection 14-1 controls the RF tag reader/writer unit 20-1 to read the IDof the reference RF tag 41. This reading operation is periodicallyperformed. Or, this reading operation is performed when the use of thereader/writer control section 14-2 has been completed.

(6) Step S206

If the RF tag reader/writer unit 20-1 cannot read the reference RF tag41, the operational flow returns to the step S205 in its original state.If the RF tag reader/writer unit 20-1 can read the reference RF tag 41,the RF tag reader/writer unit 20-1 and the antenna 30-1 can be used.Thus, in order to instruct the reader/writer switching section 12 to usethe reader/writer control section 14-1, the operational flow returns tothe step S201.

Since the data of the reference RF tag 41 is unnecessary for theapplication, the communication control section 11 removes the ID of thereference RF tag 41. If there is the read request of the data from thereference RF tag 41, this is neglected or treated as the non-existenceof the tag. If there is the read request of the RF tag positioned nearthe antenna, it is reported to the application after the ID of thereference RF tag 41 is removed from the list of the read RF tag ID.

It should be noted that the number of the reference RF tags 41 may beplural. For example, there is a possibility that data cannot be readfrom the reference RF tag 41 through the RF tag reader/writer unit 20 orthe antenna 30 due to the damage or defect of the reference RF tag 41.In this case, even if the reference RF tag 41 as a first candidate isdamaged, the check can be performed by reading the reference RF tag 41as a second candidate. If the reference RF tag 41 as the secondcandidate can be read, it is judged not to result from the trouble ofthe RF tag reader/writer unit 20 or antenna 30, and it is judged toresult from the defect of the reference RF tag 41 as the firstcandidate. Consequently, the defect of the RF tag itself can be judged.

As mentioned above, in the present invention, while the plurality of RFtag reader/writer apparatuses provided close to each other are managedand the interferences are avoided, the redundancy of the RF tagreader/writer apparatus is ensured.

1. An RF tag system comprising: a first reader/writer unit; a secondreader/writer unit; a first reader/writer control unit configured tocontrol said first reader/writer unit to read a first data from a firstRF tag, and to detect a trouble state of said first reader/writer unit;a second reader/writer control unit configured to control said secondreader/writer unit to read a second data from a second RF tag, and todetect a trouble state of said second reader/writer unit; a monitoringsection configured to issue a selection instruction and to monitor saidfirst reader/writer unit through said first reader/writer control unit,and said second reader/writer unit through said second reader/writercontrol unit; and a switching section configured to select one of saidfirst reader/writer control unit and said second reader/writer controlunit in response to the selection instruction from said monitoringsection.
 2. The RF tag system according to claim 1, wherein saidmonitoring section issues the selection instruction to said switchingsection to select said second reader/writer control unit when thetrouble state of said first RF tag reader/writer unit is confirmed. 3.The RF tag system according to claim 1, wherein said monitoring sectionissues a monitor instruction to said first reader/writer control unit todetect recovery of said first RF tag reader/writer unit from the troublestate, when the trouble state of said first RF tag reader/writer unit isconfirmed.
 4. The RF tag system according to claim 1, furthercomprising: a communication control section configured to communicatewith an external network and to transfer a data request from saidexternal network to said switching section to acquire a data of saidfirst RF tag or second RF tag.
 5. The RF tag system according to claim1, wherein said first RF tag and said second RF tag are a same singlereference RF tag provided for operation confirmation, and said first andsecond RF tag reader/writer units access said reference RF tag.
 6. Amethod of controlling a read operation from an RF tag, comprising:issuing an instruction to a switching section to use a first RF tagreader/writer control unit; inquiring said first RF tag reader/writercontrol unit to check whether said first RF tag reader/writer unit is ina trouble state; continuing to use first RF tag reader/writer controlunit by said switching section if said first RF tag reader/writer unitis not in the trouble state; issuing an instruction to said switchingsection to use a second RF tag reader/writer control unit, when it isconfirmed that said first RF tag reader/writer unit is not in thetrouble state; instructing said first RF tag reader/writer control unitto confirm whether said first RF tag reader/writer unit has beenrecovered from the trouble state, when it is confirmed that said firstRF tag reader/writer unit is not in the trouble state; and when it isconfirmed that said first RF tag reader/writer unit has been recoveredfrom the trouble state, issuing an instruction to said switching sectionto use said first RF tag reader/writer control unit.
 7. The methodaccording to claim 6, further comprising: issuing a data read requestfrom an application connected to an external network; receiving the dataread request from said application and transferring the data readrequest to said switching section; and controlling one of said first RFtag reader/writer control unit and said second RF tag reader/writercontrol unit in response to the data read request to read a data fromthe RF tag.
 8. The method according to claim 6, further comprising:issuing a read instruction to said first RF tag reader/writer controlunit to read a data from the RF tag, when it is confirmed that saidfirst RF tag reader/writer unit is not in the trouble state; andcontrolling said first RF tag reader/writer unit to access the RF tag toread the data by said first RF tag reader/writer control unit inresponse to the read instruction.
 9. The method according to claim 6,further comprising: issuing a read instruction to said second RF tagreader/writer control unit to read a data from the RF tag, when it isconfirmed that said first RF tag reader/writer unit is in the troublestate; and controlling said second RF tag reader/writer unit to accessthe RF tag to read the data by said second RF tag reader/writer controlunit in response to the read instruction.